Adverse possession—sometimes called squatter's rights—occurs when a person or entity who does not own a certain piece of real property occupies or uses it in a way that is adverse to the owner of the property—meaning the use is in conflict or at odds with the property owner’s interests.

If this adverse possession or use of the property meets the legal standard for adverse possession—often described as use that is continuous, exclusive, hostile, open, and notorious—and continues for the prescribed period of time (usually specified in the state statute)—the person or entity adversely possessing or using the property will acquire ownership of the property (title). This ownership will result in the changing of boundary lines.

Because the required adverse possession must be open, obvious, and adverse to the owner’s interests, title may only be acquired by adverse possession to the portion of property that is used in that way.

Adverse possession laws vary from state to state and may be located in a state’s court opinions (also known as common law or case law) or, more often, in its statutes.

In Michigan, adverse possession laws allow a person to claim ownership of a property if they have occupied it in a manner that is hostile, actual, open, notorious, exclusive, and continuous for a statutory period, which is typically 15 years. The occupation must be such that it would give the legal owner a cause of action for trespass, and the possessor must not have the owner's permission to use the property. The claimant must also pay taxes on the property during this period. If these conditions are met, the person claiming adverse possession can file a lawsuit to obtain legal title to the property. It's important to note that adverse possession is a complex area of law, and anyone considering or contesting a claim of adverse possession should consult with an attorney to understand the specific requirements and legal implications.